Parentage and relatedness determination in farmed Atlantic salmon (Salmo salar) using microsatellite markers

This study demonstrates how both parentage and relatedness can be determine d in a mixed family aquaculture (Atlantic salmon) stock in the absence of p hysical tags and/or pedigree information. Under a number of different scena rios, both real and simulated, we could use microsatellite markers to assig n parentage to offspring with varying degrees of accuracy. The precision of assignment to one correct parental pair depended not only on the number an d variability of the microsatellite markers, but also on the number of pote ntial pairings from which to choose, i.e., the more families in the breedin g program the more microsatellites required to discriminate between them. U sing eight highly variable markers resulted in an assignment of an individu al to the correct parental pair of greater than 95% even when the number of possible parent pairs is > 12,000. These same microsatellite loci were cap able of discriminating between related and unrelated individuals in a situa tion where no pedigree information is known. Based on these results we conc lude that the use of a number of microsatellite markers represents a realis tic and cost-effective alternative to physical tagging in a family selectio n program. (C) 2000 Elsevier Science B.V. All rights reserved.